Enhanced Oil Recovery in Post-CHOPS Cold Heavy Oil Production withSand Heavy Oil Reservoirs of Alberta and Saskatchewan Part 1:FieldPiloting of Mild Heating Technologies

摘要

Lloydminster area that straddles Alberta and Saskatchewan border contains vast amounts of heavy oildeposits in thin unconsolidated formations.It is believed that the heavy oil resource volume is in the 50to 70 billion bbl range which makes it a world class resource.This work briefly summarizes the reservoirproperties of these formations and provides an overview of the primary CHOPS recovery mechanism whichonly recovers on average 8% of the original oil in place.Therefore,the target for Enhanced Oil Recovery(EOR)processes are substantial.For instance,if an additional 2%(25% of the primary)oil can be recovered,this means an additional 1 to 1.5 billion bbls of oil production which can sustain the oil industry for manyyears in this area providing jobs and contributing significantly to government royalties.A number of EOR processes are reviewed in this study from the conventional water flooding technologiesto more state of the art processes such as Horizontal well Hot Oil Circulation.It is shown that part of theresource with viscosities less than 5,000 to 10,000 cp can be a target for water/polymer flooding.While steam injection in heavy oil reservoirs can be very successful,more than 95% of the resourcein Lloydminster is less than 10 m thick and,thus,is not amenable to steam injection due to excessiveheat losses to the surrounding formations.However,EOR processes involving mild heating or no heatingcan be feasible in these thinner formations.A number of mild heating technologies are discussed.Two ofthese technologies have been piloted in the field:Hot Water Vapour Process and Horizontal Well Hot OilCirculation.Field results from these pilots are presented and discussed in this paper.It appears that thesetechnologies can offer significant commercial potential in post-CHOPS reservoirs as well as in areas whereCHOPS or horizontal primary production wells have not been successful.